NVM or Non-volatile memory is a type of computer memory that can store all the data present in it regardless if the memory has power or not. In simple words, if the power to memory is disabled then it will still be able to hold the data stored in it.
They are totally opposed to the volatile memory in which the data is completely erased as soon as the power is disabled. Also unlike Volatile memory, non-volatile memory does not need to be refreshed periodically.
Some examples of Non-volatile memory are Hard-Disk, Flash Drives (Pen drives), ROM.
Credits- Google Images
Non-volatile memory is majorly used for long-term data storing solutions or secondary solutions. Most common use of this type of memory is in our laptops and desktop where the hard-drives are the non-volatile memory. Of course, we don’t want our data to be erased as soon as we turn off our systems. ROM memory stays there when you turn the computer off, your programs and movies are still there the next time you turn on.
Difference between Volatile and Nonvolatile memory
Volatile memory requires electricity or some kind of current to store information, and non-volatile memory does not. Most computers have both types of memory. Random access memory is an example of volatile memory, and read only memory is an example of non-volatile memory.
With volatile memory, the current that runs through the computer is what helps hold the memory. With RAM, the operating system only uses this memory during operations. Once the power is turned off, the RAM is wiped clear. Non-volatile memory does not require any kind of power to hold information. This is why people use ROM and flash memory to store pictures, documents and other important information. Once the power of the computer is turned off, the important information still exists and is accessible later.
Volatile memory tends to run faster than non-volatile memory. That is why computers use volatile memory for tasks that require fast response times and need memory for only small intervals of time. Non-volatile memory tends to be slower because it has to write and record the data so that users can call on it again. Non-volatile memory is also rewritable, which means that users have the ability to delete the information that is stored on it.
Non-volatile memory types
Non-volatile data storage can be categorized in electrically addressed systems (read-only memory) and mechanically addressed systems (hard disks, optical disc, magnetic tape, holographic memory, and such). Electrically addressed systems are expensive, but fast, whereas mechanically addressed systems have a low price per bit, but are slow. Non-volatile memory may one day eliminate the need for comparatively slow forms of secondary storage systems, which include hard disks.
Importance of Non-Volatile Memory
Non-volatile memory is very important for our systems as there are some sensitive system files which need to be present on the memory as soon as the system is turned on. In order to fulfil this requirement, NVM comes to our rescue. It gives the system the required information and helps in proper working. Because the volatile memory(RAM) loses all the data as soon as it is turned off so while shutting down all the data is transferred to Hard Disk(NVM).
The system needs a very fast memory to operate smoothly. As the non-volatile memory is not very fast so it can not directly operate with the system and is used to store all the data while powering off the system. As soon as the system is turned on all the required system files are taken from NVM and copied into the RAM (volatile memory). This way NVM plays a crucial role in working with a system.